sarvah samuddhared raja
piteva vyasanat prajah
atmanam atmana dhiro
yatha gaja-patir gajan
Just as the chief bull elephant protects all other elephants in his herd and defends himself as well, similarly, a fearless king, just like a father, must save all of the citizens from difficulty and also protect himself.
Lord Krsna, having concluded His discussion of brahminical duties, now describes the character and activities of a king. Protecting all of the citizens from difficulty is an essential duty for the king.